1. Field of the Invention
The invention relates to a rail wheel with a wheel-mounted brake disk, which by virtue of multiple fastening elements distributed across the wheel circumference is fastened to the wheel body of the rail wheel and is seated against the wheel body in this fastening region.
In this case, only one wheel-mounted brake disk may be provided on one side of the wheel, or two wheel-mounted brake disks may be provided, one on each side of the wheel. Multiple concentric wheel-mounted brake disks on one or on both sides of the wheel are also conceivable.
In rail vehicles, the wheel is usually designed as a monobloc wheel, i.e., as a disk wheel. In these vehicles, the wheel body comprises the wheel web and the wheel hub. However, the invention is not restricted to monobloc wheels.
2. Description of the Related Art
Rail vehicles generally utilize a plurality of braking systems, where a brake controller coordinates the interaction of all braking systems. In this case, the most important braking system is the friction brake. This converts the kinetic energy of a rail vehicle into heat using two friction partners. In this case of high-speed trains, the friction partners are brake disks made of steel and brake pads made of sintered metal.
Here, the brake disks can be embodied as wheel-mounted brake disks. The braking torque is transmitted from the wheel-mounted brake disk to the wheel via a force-locking connection, usually a screwed connection. During braking, a very high output is introduced into the wheel-mounted brake disk and the latter is as a result thermally deformed. The thermal deformation places great stress on the fastening elements which, where applicable, causes considerable loosening of the screwed connection, and may even result in the loss of the screw prestressing force. This results in the screwed connection coming undone or failing.
Hitherto, this problem was solved by seating the wheel-mounted brake disk with its cooling fins completely against the wheel body, more specifically the wheel web, and the screwed connection was designed such that despite the loosening the remaining screw prestressing force is sufficient to transmit the braking torque. Such arrangements are known from the introductory part of the description of DE 10 2008 003 923 A1, which itself in turn discloses a rail the wheel in which a shim is provided in the contact region between wheel-mounted brake disk and wheel body.
Another possibility for ensuring sufficient screw pre-stressing is to connect the wheel-mounted brake disk for transmission of the braking torque additionally in form-lock manner to the wheel, so that a lesser amount of stress is placed on the screwed connections.